The goal of periodontal treatments is to eliminate bacteria and their products without
damaging cementum surfaces. Nonsurgical treatments are often limited by the
inability of curettes to access the most apical zone of the pocket. While ultrasonic
mini-inserts have been used for nearly 10 years now, their effect on dental tissues
has not been tested. The purpose of the present study was to compare a new series
of mini-inserts to Gracey curettes, which are the reference in nonsurgical treatments.
Two experienced periodontists conducted root treatments on teeth destined for
extraction using regular clinical criteria. One face of each root was instrumented
using a Gracey curette, and the opposite face was instrumented using an ultrasonic
mini-insert. After the instrumentation procedure, the teeth were prepared for examination
by secondary electron (topographic features) and backscattered electron
(organic and mineral composition) microscopy. Differences in surface composition
between teeth treated by the two periodontists were noted and were related to the
lateral pressure exerted. Calculus removal was less effective when strong lateral
pressure was exerted using the ultrasonic mini-inserts, while more cementum was
removed and more scratching occurred with both manual and ultrasonic instruments.
In all cases, the ultrasonic mini-inserts allowed greater apical access. The new
ultrasonic mini-inserts were as effective as manual curettes in eliminating plaque and
calculus. The shape of the mini-inserts made them more effective in apical zones.
The amount of damage to the cementum depended on the lateral pressure exerted
by the periodontist. (Int J Periodontics Restorative Dent 2004;24:137–145.)

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